Konishiroku Photo Industry Co., Ltd.

Konica Corporation

Mitsubishi Kasei Corporation

Masafumi Uehara

Akira Nogami

Kazuhiro Shimura

Fumio Shimada

Masatoshi Matsuzaki

Akio Iwaki

Shinya Watanabe

Minoru Seino

Miegi Nakano

Shinichi Matsubara

Takeshi Yamamoto

Atsuo Yamazaki

Shinichi Bunya

Mitsuyoshi Itano

Eriko Katahashi

Yoko Ogawa

Kiyoshi Goto

Toshiyuki Matsumura

Keiichi Yumiki

Tohru Aoki

The improved method of development is implemented with an automatic processor for developing presensitized offset printing plates with a substantially virgin aqueous solution that contains an alkali silicate and that is supplied for each printing plate, said aqueous solution containing calcium ions in an amount of up to 10 mg/L. The improved developing apparatus comprises a means of mixing a concentrated developing solution with diluent water to prepare a working solution and a means of applying the working solution onto the surface of a presensitized offset printing plate being transported. The apparatus is characterized by further including a mechanism that performs ion-exchange on the diluent water before it is mixed with the concentrated developing solution.

Method and apparatus for developing presensitized offset printing plates

Disclosed is a photosensitive composition comprising a diazo resin and a polymeric compound containing a structural unit represented by the following formula (I) in the molecule: ##STR1## wherein J represents a divalent linking group and n is 0 or 1. Disclosed is also a photosensitive lithographic printing using the photosensitive composition.

Photosensitive composition and photosensitive lithographic printing

A developing solution of an imagewise exposed, presensitized offset printing plate is disclosed. The developing solution has a pH of at least 12.5, and contains a low content of a silicate in an amount of up to 1.0 wt % as SiO.sub.2, a surfactant in an amount of 0.01 to 10 wt %, an aromatic carboxylic acid in an amount of 0.1 to 10 wt %, and an amine compound represented by the following general formula (I) in an amount of 0.1 to 10 wt %:

Method of developing presensitized offset printing plates and developing

Disclosed are a method and an apparatus for processing with a developing solution repeatedly used, both an imagewise exposed, positive-working presensitized lithographic printing plate and an imagewise exposed negative-working presensitized lithographic printing plate. The plates each comprise an aluminum support and a light-sensitive layer formed thereon. A replenishing solution is added to the developing solution to compensate for the degradation of the developing solution brought about by development and/or by carbon dioxide in the air. The method comprises the steps of; measuring a reflection density of the light-sensitive layer of the printing plates to discriminate the type of the printing plate, selecting a predetermined developing condition according to the discriminated type of the printing plate, and developing the printing plates according to the selected developing condition.

Method and apparatus for processing presensitized lithographic printing

A method of developing a waterless light-sensitive lithographic printing plate having a support and, provided thereon, a light-sensitive layer comprising a diazo resin and a silicone gum layer with a developer is disclosed. The developer comprises an organic carboxylic acid or salt thereof, water, and at least one of a sulfite and a surfactant.

Method for developing a waterless light-sensitive lithographic plate

There are disclosed an aqueous alkaline developer for light-sensitive lithographic printing plate commonly processing a negative-type light-sensitive lithographic printing plate having a light-sensitive layer containing a diazo compound and a positive-type light-sensitive lithographic printing plate having a light-sensitive layer containing an o-quinonediazide compound, which comprises containing an alkali agent, 0.1 to 10% by weight of a water-soluble reducing agent, a sodium, potassium or ammonium salt of an organic carboxylic acid, and a non-ionic or cationic surfactant, and having a pH in the range of 12.5 to 13.5, and also a developer composition for light-sensitive material, which comprises an aqueous solution containing a compound represented by the formula (I) shown below: ##STR1## wherein R.sub.1 represents an alkyl group or an alkoxy group each having 2 to 5 carbon atoms, or a hydroxyalkyl group having 2 to 5 carbon atoms; and R.sub.2 represents a hydrogen atom, a halogen atom, an amino group, a hydroxyl group, an alkyl group, an alkoxy group or a phenyl group.

Developer for light-sensitive lithographic printing plate capable of

An apparatus for processing an imagewise exposed pre-sensitized lithographic printing plate which entails uniformly applying a desired amount of developer, that has not been substantially used to the surface of the printing plate by a developer supply member comprised of two plates and having a slit at the lowermost portion thereof which contacts the surface of the printing plate, and then transferring the plate containing the developer to a developer storage tank, immersing the plate in the developer storage tank, and removing the developer from the plate.

Method of processing pre-sensitized lithographic printing plate and

A photosensitive composition, comprising a photosensitive diazo compound and a polymeric binder, wherein the diazo compound has a polymerizable unsaturated bond in the molecule.

Photosensitive composition

A method of processing an imagewise exposed pre-sensitize lithographic printing plate which entails uniformly applying a desired amount of developer, that has not been substantially used to the surface of the printing plate by a developer supply member comprised of two plates and having a slit at the lowermost portion thereof, and then transferring the plate containing the developer to a developer storage tank, immersing the plate in the developer storage tank, and removing the developer from the plate.

Methods of processing pre-sensitized lithographic printing plate and

A method and a device of dividing an aqueous processing waste solution of a non-silver halide light-sensitive material into solid and water are disclosed comprising the steps of:

Method of treating an aqueous processing waste solution of a non-silver

A process for forming a printing plate use a specific electrophotographic material for obtaining a toner image which comprises a support and a layer for obtaining an electrostatic latent image coated thereon, said layer being composed mainly of a phenol resin containing a phthalocyanine pigment and having a specific repeating unit.

Process for forming printing plate using an electrophotographic material

A positive-working photosensitive composition comprising (a) an o-quinonediazide compound and (b) a condensed resin containing a condensation unit composed of an aromatic compound having a carboxylic group and a phenolic ahydroxyl group, and an aldehyde or ketone is disclosed. Said condensation unit has the following formula (I): ##STR1## wherein R.sub.1 is a hydrogen atom, a hydroxyl group, an acyloxy group, an alkyl group, an alkoxy group or a halogen atom, which may be the same or different when n is 2; R.sub.2 and R.sub.3 are each a hydrogen atom, a lower alkyl group having 1 to 4 carbon atoms, a phenyl group or a substituted phenyl group, which may be the same or different; and n is 1 or 2.

Positive-working photosensitive composition with o-quinone diazide and

There is disclosed a photosensitive composition comprising an o-quinonediazide compound and, as a binder resin, a resin containing in the molecule the unit represented by the following formula ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 have the same meanings as defined in the specification. The photosensitive composition according to the present invention has excellent resistance to chemicals and long press-life, and is excellent in alkali-solubility and difficult to form scumming.

Photosensitive compositions

A posi-type photosensitive composition having enhanced sensitivity is prepared by incorporating a specific sensitizer selected from gallic acid, its derivative, naphthoquinone compound and its derivative in a quinonediazide type photosensitive material. The composition is free from lowering in development tolerance and other properties.

Posi-type quinone diazide photosensitive composition with sensitizer

The present invention relates to an ink composition for ink-jet recording. The ink is an aqueous solution comprising a water soluble acid or direct dye or mixtures thereof and a compound selected from the class of polyhydric alcohols having 1-4 carbon atoms, hexylene glycol, triethylene glycol, di-propylene glycol and 1,2,6-hexanetriol. The composition of this invention has a viscosity of from 4-20 c.p.s., a surface tension of from 40-60 dyn/cm and a specific resistance of from 5.times.10.sup.3 -1.times.10.sup.5 ohm cm.

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Hino, Japan

Masafumi Uehara